Why Do Birds Molt?

Birds molt because their feathers wear out, as clothes do, and need to be replaced. The process is called “molting.” Birds molt their feathers at least once a year, in late summer or early fall.

Feathers are dead structures at maturity which are gradually abraded and need to be replaced. Feathers are made from a substance called “keratin.” It is basically the same material your hair is made of.

In molting, old worn feathers drop out of their sockets in a bird’s skin and new ones grow in their place. Some birds grow bright, new feathers for the nesting season. These birds molt twice a year. Most birds molt just a few feathers at a time, so they are able to fly during molting periods.

It is generally a slow process as birds rarely shed all their feathers at any one time; the bird must retain sufficient feathers to regulate its body temperature and repel moisture. The number and area of feathers that are shed varies.

In some molting periods, a bird may renew only the feathers on the head and body, shedding the wing and tail feathers during a later molting period. Some species of bird become flightless during an annual “wing molt” and must seek a protected habitat with a reliable food supply during that time.

Content for this question contributed by Kristy Montgomery, resident of Healdsburg, Sonoma County, California, USA